Determination of the required amount of bone graft for sinus lifting procedures of the maxilla posterior tooth deficiency area

It is known that the maxillary posterior region is risky area for implant survival due to insufficient bone quality, sinus pneumatization and alveolar bone resorption. In order to place the implant in the ideal length and appropriate position into the area, bone augmentation procedures are planned when the residual bone height can not provide the primary stability of the implant to be placed. In this retrospective study, it is aimed to calculate the amount of bone grafts required to place the implant in the ideal length for the patients who need maxillary sinus floor elevation and grafting. In addition to this also the effects of bone thickness, toothed / edentulous termination, age and gender on graft amounts were analyzed. Cone beam computed tomography images of the patients were analyzed in two and three dimensions using a retrospective database. It has been detected that a total of 241 individuals (107 men and 134 women) need implants in 429 maxilla posterior region. After the measurements, it has been determined that 200 regions require sinus floor elevation by lateral approach. Three-dimensional segmentation was used in these regions and the required amount of bone was recorded in units of cubic millimeter volumetrically. According to the results of the study; It was determined that when the residual bone height decreased, the thickness of the sinus lateral wall also decreased, the toothed-terminated regions needed significantly more bone grafts than the toothless-ended regions, and male needed significantly more bone grafts than famale (p <0.05). A moderate negative correlation was found between the residual bone height and the bone volume to be reconstructed (p = 0.000, r = -0.557). In the light of these findings, it is thought that residual bone height and lateral wall thickness in the maxilla posterior region are important measurements that should be evaluated before sinus floor elevation applications, and pre-operative estimation of the amount of bone graft used in sinus augmentation within the limits of this study will have important contributions in terms of health economics. Keywords: Maxillary sinus elevation, bone graft, lateral wall thickness